1. Field
The disclosed concept relates generally to electrical switching apparatus and, more particularly, to electrical switching apparatus, such as circuit breakers. The disclosed concept also relates to mounting assemblies for circuit breakers.
2. Background Information
Electrical switching apparatus used in power distribution systems are often mounted within a switchgear enclosure either individually or in combination with other switchgear (e.g., without limitation, circuit switching devices and circuit interrupters such as circuit breakers, contactors, motor starters, motor controllers and other load controllers).
Some electrical switching apparatus such as, for example, some medium-voltage and low-voltage circuit breakers, can be relatively large. In order to facilitate movement (e.g., installation; removal; maintenance), some circuit breakers are commonly coupled to draw-out mechanisms which permit such circuit breakers to be drawn out of the switchgear enclosure. Accordingly, such circuit breakers are commonly known in the art as “draw-out” circuit breakers. The circuit breaker may be further supported within a draw-out frame, commonly known in the art as a cassette or chassis. The switchgear enclosure generally includes a number of cells, with each cell being structured to receive a corresponding circuit breaker, and a number of closeable doors for enclosing the circuit breaker(s) within the enclosure. The draw-out mechanism includes, for example, a combination of rails and rollers coupled to one or the other, or both, of the sidewalls of the cell and the sides of the corresponding circuit breaker, which is to be drawn into and out of the cell. Draw-out circuit breakers are described in further detail, for example, in commonly assigned U.S. Pat. No. 7,019,229, which is hereby incorporated herein by reference.
To prevent injury (e.g., electrical shock), it is often desirable to limit access to energized electrical equipment within the enclosure. For example, in order to perform maintenance on a draw-out circuit breaker, the interior of the circuit breaker must be accessed, for example, by drawing the circuit breaker out of the enclosure. Improper maintenance procedures (e.g., failure to first de-energize or turn the circuit breaker OFF) could cause serious injury to maintenance personnel and damage to the electrical equipment. Accordingly, a variety of remotely operated devices such as, for example and without limitation, remotely operated racking devices and circuit breaker controls, have been developed as a safety measure for protecting personnel who work on or near energized electrical equipment. However, among other disadvantages, known devices of this type require modification of the existing switchgear enclosure, circuit breaker or electrical equipment, are mounted on the door or cover of the enclosure or circuit breaker by a relatively complex mounting hardware assembly, and/or require the door or cover to be opened potentially subjecting the operator to danger.
There is, therefore, room for improvement in electrical switching apparatus, such as circuit breakers, and in mounting assemblies therefor.